A field experiment was carried out to evaluate the efficiency of some herbicide treatments (with and without handweeding) on sugar beet yield and yield components for two successive seasons (2010 and 2011) at Abbis farm, Faculty of Agriculture, Alexandria University, Alexandria, Egypt.
The treatments were Phenmedipham 6.5%+ metametron 28% + ethofumesate 6.5% (crus) with a rate of 2 kg/feddan and 2.5 kg/feddan, Phenmedipham 5.54% + desmedipham 4.34% + lenacil 2.5% + ethofumesate 6.93 (betanal maxxpro), acetochlor (harness), Phenmedipham 7.5% + desmedipham 1.5% + ethofumesate 11.5% (betasana trio), handweeding twice and Unweeded check, all previous herbicide treatments were repeated twice either with or without handweeding.
The dominant weed in both seasons was Beta vulgaris. The results in the first season showed that the best herbicide treatments which gave maximum weed reduction were handweeding twice, Acetochlor + handweeding, (Phenmedipham 6.5% + metametron 28% + ethofumesate 6.5%) 2.5 kg/fed + handweeding , (Phenmedipham 6.5% + metametron 28% + ethofumesate 6.5%) 2 kg/fed + handweeding, (Phenmedipham 7.5% + desmedipham 1.5% + ethofumesate 11.5%) + handweeding and (Phenmedipham 5.54% + desmedipham 4.34%+ lenacil 2.5%+ ethofumesate 6.93%) + handweeding with no significant differences between them with a percentage of weed control (98.7, 97.7, 96.7, 96.2, 95.8 and 93.7), respectively.
In the second season the best weed reduction was achieved by (Phenmedipham 6.5% + metametron 28% + ethofumesate 6.5%) with a rate of 2.5kg/fed + handweeding with a percentage of control (97.3%), handweeding twice (96.8%), (Phenmedipham 6.5% + metametron 28% + ethofumesate 6.5%) with a rate of 2kg/fed+ handweeding (96.1%), Acetochlor + handweeding (95.8%), (Phenmedipham 7.5%+ desmedipham 1.5% + ethofumesate 11.5%) + handweeding (93.6%) and (Phenmedipham 5.54% + desmedipham 4.34%+ lenacil 2.5%+ ethofumesate 6.93%)+ handweeding (91.6%) with no significant differences between them.
The highest yield in the first season was found in the case of (Phenmedipham 6.5%+ metametron 28% + ethofumesate 6.5%) 2.5 kg/fed which gave 35.32 ton/fed followed by handweeding twice with a yield 31.82 ton/fed and (Phenmedipham 5.54%+ desmedipham 4.34%+ lenacil 2.5%+ ethofumesate 6.93%) with a yield 29.59 ton/fed with no significant differences between them in the second season the highest feddan production was reported in the case of (Phenmedipham 6.5%+ metametron 28%+ ethofumesate 6.5%) 2.5 kg/fed+ handweeding and handweeding twice (34.23 and 33.18 ton/fed, respectively) with no significant difference between them.
The length and diameter of the root were not affected by the tested herbicides, also the percentage of sugar were not affected by all treatments, but in the first season, the highest sugar yield per feddan was found in the case of five treatments which were (Phenmedipham 6.5%+ metametron 28% + ethofumesate 6.5%) 2.5 kg/fed + handweeding, (Phenmedipham 5.54% + desmedipham 4.34%+ lenacil 2.5%+ ethofumesate 6.93%) + handweeding, handweeding twice, (Phenmedipham 6.5%+ metametron 28% + ethofumesate 6.5%) 2 kg/fed+ handweeding and (Phenmedipham 6.5% + metametron 28% + ethofumesate 6.5%) 2.5 kg/fed with sugar yield (5.4, 4.98, 4.73, 4.64 and 4.35 ton/fed, respectively with no significant differences between them while in the second season the four treatments that gave highest yield were (Phenmedipham 6.5% + metametron 28% + ethofumesate 6.5%) 2.5 kg/fed+ handweeding, handweeding twice, acetochlor+ handweeding and (Phenmedipham 7.5%+ desmedipham 1.5% + ethofumesate 11.5%) + handweeding as they gave (5.58, 5.28, 4.93 and 4.64 ton/fed, respectively.